Add base layer root methods.

Author: cstancu

substratevm/src/com.oracle.graal.pointsto/src/com/oracle/graal/pointsto/meta/AnalysisMethod.java

@@ -353,14 +353,14 @@ public boolean isDelayed() {
         return compilationBehavior == CompilationBehavior.FULLY_DELAYED_TO_APPLICATION_LAYER && buildingSharedLayer;
     }
 
-    public void setPinnedToInitialLayer() {
+    public void setPinnedToInitialLayer(Object reason) {
         BigBang bigbang = getUniverse().getBigbang();
         AnalysisError.guarantee(bigbang.getHostVM().buildingInitialLayer(), "Methods can only be pinned to the initial layer: %s", this);
         boolean nonAbstractInstanceClass = !declaringClass.isArray() && declaringClass.isInstanceClass() && !declaringClass.isAbstract();
-        AnalysisError.guarantee(nonAbstractInstanceClass, "Only methods from non abstract instance class can be delayed: %s", this);
-        bigbang.forcedAddRootMethod(this, true, "Method is pinned to the initial layer");
+        AnalysisError.guarantee(nonAbstractInstanceClass, "Only methods from non abstract instance class can be pinned: %s", this);
+        bigbang.forcedAddRootMethod(this, true, "pinned to initial layer: " + reason);
         if (!isStatic()) {
-            declaringClass.registerAsInstantiated(this + " is pinned to the initial layer");
+            declaringClass.registerAsInstantiated("declared method " + this.format("%H.%n(%p)") + " is pinned to initial layer: " + reason);
         }
         setNewCompilationBehavior(CompilationBehavior.PINNED_TO_INITIAL_LAYER);
     }

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/imagelayer/InitialLayerFeature.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2025, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.svm.hosted.imagelayer;
+
+import com.oracle.graal.pointsto.meta.AnalysisMetaAccess;
+import org.graalvm.nativeimage.hosted.Feature;
+
+import com.oracle.svm.core.feature.AutomaticallyRegisteredFeature;
+import com.oracle.svm.core.feature.InternalFeature;
+import com.oracle.svm.core.imagelayer.ImageLayerBuildingSupport;
+import com.oracle.svm.hosted.FeatureImpl.BeforeAnalysisAccessImpl;
+import com.oracle.svm.util.ReflectionUtil;
+
+import jdk.internal.misc.Unsafe;
+
+@AutomaticallyRegisteredFeature
+public class InitialLayerFeature implements InternalFeature {
+    @Override
+    public boolean isInConfiguration(Feature.IsInConfigurationAccess access) {
+        return ImageLayerBuildingSupport.buildingInitialLayer();
+    }
+
+    @Override
+    public void beforeAnalysis(BeforeAnalysisAccess a) {
+        BeforeAnalysisAccessImpl access = (BeforeAnalysisAccessImpl) a;
+
+        /*
+         * Make sure that critical VM components are included in the base layer by registering
+         * runtime APIs as entry points. Although the types below are part of java.base, so they
+         * would anyway be included in every base layer created with module=java.base, this ensures
+         * that the base layer is usable regardless of the class inclusion policy.
+         */
+        String pinReason = "base layer entry point included unconditionally";
+        AnalysisMetaAccess metaAccess = access.getMetaAccess();
+        metaAccess.lookupJavaMethod(ReflectionUtil.lookupMethod(Unsafe.class, "getUnsafe")).setPinnedToInitialLayer(pinReason);
+        metaAccess.lookupJavaMethod(ReflectionUtil.lookupMethod(Unsafe.class, "allocateInstance", Class.class)).setPinnedToInitialLayer(pinReason);
+        metaAccess.lookupJavaMethod(ReflectionUtil.lookupMethod(Runtime.class, "getRuntime")).setPinnedToInitialLayer(pinReason);
+        metaAccess.lookupJavaMethod(ReflectionUtil.lookupMethod(Runtime.class, "gc")).setPinnedToInitialLayer(pinReason);
+        metaAccess.lookupJavaMethod(ReflectionUtil.lookupMethod(Class.class, "getResource", String.class)).setPinnedToInitialLayer(pinReason);
+    }
+
+}